In recent years, a technique has been presented in which a two-dimensional code is taken by a camera, code data is recognized and a predetermined process associated with the code data is executed. Various types of two-dimensional codes are in practical use at present, since a two-dimensional code can include more coded information, in comparison with a one-dimensional bar code. Under these circumstances, a technique relating to image recognition of a two-dimensional code has been conventionally presented (for example, see Patent Document 1).
In order to acquire a three-dimensional position or the like of an object located in the real space, a technique has been presented in which a three-dimensional position or a three-dimensional posture is recognized by flashing each of a plurality of LEDs equipped on the object in a uniquely determined flashing pattern, respectively, and using images captured by a two-dimensional image sensor (for example, see Patent Document 2). In Patent Document 2, an LED serving as a marker has the identification information which can be uniquely identified for each LED.    Patent Document 1: Japanese Patent Laid-Open No. 2000-82108;    Patent Document 2: Japanese Patent Laid-Open No. 2003-254716.